Fluency with Information Technology INFO100 and CSE100 Katherine Deibel 2012-04-18Katherine Deibel, Fluency in Information Technology1

When IT Goes BadRadiation Warning Ahead

Fluency with Information Technology

INFO100 and CSE100

Katherine Deibel

2012-04-18 Katherine Deibel, Fluency in Information Technology 1

Project 1B

Get started now We will try to get the grades for 1A

back by Monday Unless you have concerns about image

usage permissions or your topic, you are probably fine to go


Failure

We live in an IT-dominated world When IT goes bad, we feel the impact

It can be subtle or big The blame for bad IT

Software design

User interface

Usage policies

Obsolescence


Malformed HTMLAn all too common problem


Rendering and Interpretation

Remember, HTML are instructions for how the browser renders the page

The code is interpreted You have to imagine how the browser will

display the code

This can lead to surprises


Oops: What Is Displayed?

is displayed in Firefox as:Solve for x and y where 2<8 and 0x? Show work.

What happened? Firefox interpreted <'s and >'s as tag

delimiters, not as mathematical symbols


<p> Solve for x and y where 2<x<8 and 0<y (i.e. y is a positive number) and x*y=42. Is y>x? Show work.</p>

Malformed XHTML

is displayed in Firefox as:Solve for x and y where 2<8 and 0x? Show work.

Is displayed in IE as:Solve for x and y where 2x? Show work.

Is displayed in Chrome as:Solve for x and y where 2<x<8 and 0<y (i.e. y is a positive number) and x*y=42. Is y>x? Show work.



Malformed XHTML

Why don't they display the same thing? Each browsers handles malformed HTML in its

own way.

Can vary between versions of the browsers Browsers behave differently!

Interpret XHTML standards differently

Perform page layout differently


Escape Sequences

List of escape sequenceshttp://www.escapecodes.info/

< < √ √> > £ £

& & à à© © á á" " ö ö


http://www.escapecodes.info/

http://www.escapecodes.info/

Malformed XHTML

How do we print what we originally intended? escape sequence: a sequence of

characters (prefixed by a special symbol, the escape character) that takes on an alternative interpretation (i.e., escapes normal interpretation)



The Correct Version



& and URLs

Common to see ampersands in URLs:http://www.flickr.com/search/?q=cats&l=deriv

& is used as a delimiter between options To make a link to these pages, one

needs to replace the & with & This is required for strict XHTML validation

The browser will handle the translation


Serious RepercussionsI did warn your about the radiation


Major Nuclear Accidents

International Nuclear Event Scale is used to rate the severity of nuclear and other radiation accidents Scale of 0-7

Ordinal only (no quantitative difference between any two levels)


The Worst of INES

Level 7: Cause: Chernobyl Design/policies

Fukushima Earthquake/tsunami

Level 6: Cause: Kyshtym Design/policies

Level 5: Cause: Windscale Fire Design

Goiânia Improper waste disposal

Three Mile Island Bad IT


Three Mile Island

Nuclear power plant in Pennsylvania Accident: March 28, 1979

A relief valve was accidentally left in the open position for a long period of time

Open valve caused reactor coolant to drop to dangerous levels

Overheating core had a partial meltdown Reason: Faulty indicator light on the

operation console


Bad GUI! BAD!

Status indicator for a relief valve ON: valve open

OFF: valve closed How it ran:

1. I tell the console to close the valve

2. Console turns off light

3. Console tells valve to close


How It Should Have Run

1. I tell the console to close the valve

2. Console tells valve to close

3. Valve attempts to close

4. Valve send status back to console

5. Console updates light based on status


Repercussions

With faulty information, operators performed the wrong actions Believed there was too much coolant water when

there was not enough

Partial core meltdown

Radioactive gases were allowed to vent for a long amount of time

Fortunately, the impact was small No immediate deaths

Some [questionable] spikes in cancer rates nearby


But hey…

No immediate deaths… right?


The Software That Killed

Therac-25 A radiation therapy machine used in the

mid-1980s for cancer treatments

Successor to previous successful models Responsible for at least 6 incidents of

radiation poisoning Three individuals died


How Therac-25 Worked

Two modes of function Direct beam (low-energy)

Megavolt X-ray (high energy) Megavolt X-ray mode used targets to

Shape the beam

Control its strength


The Problem

Therac-25 would sometimes shift into Megavolt X-ray mode when it should have been in direct mode Not a problem if targets were in place

But they weren't Furthering the problem was that it

appeared to happen randomly There were patterns


Multiple Issues

Old software, new hardware Previous models had expensive hardware

interlocks that prevented the high-energy beam from firing without targets

Interlocks were removed but software still assumed they were there (and not sending errors)


Multiple Issues

Unhelpful error messages/warnings The software would sometimes warn the

user with a "helpful" message:

ERROR 50

Being human, the operator would ignore it and proceed


Multiple Issues

Poor software design led to two major problems: race conditions and overflow Equipment and user console did not synchronize

properly Arithmetic overflow

Software incremented a variable to indicate a specific status was true

If status was marked true multiple times, overflow occurred: 255 + 1 0

0 indicated the status was false (when really true)


Therac-25 Today

Not in use… whew Classic case study of how NOT to

design safety-critical systems


Sadly all too common

Software and interfaces are known to cause multiple accidents

For a humorous view on some examples, a recent Cracked article: http://www.cracked.com/article_19776_6-

disasters-caused-by-poorly-designed-user-interfaces.html


More Subtle Bad ITIt's still out there


Search and Society

Many of us turn to search for making daily decisions Where to go to eat

What to buy

How to get there

What is the meaning of… What happens when the search is

manipulated behind the scenes?


Googlebombing

Embedding links in web pages to change Google Search results

Positive and negative uses Positive:

Prevent an anti-semitic site from being the first result for 'jew'

Negative:Link "dumb motherf***er" to George W. Bush during the 2000 elections


Google Search Suggestions

When you type into the search box, it gives autocomplete suggestions

Certain search words are prevented Bittorrent, torrent, utorrent, megaupload,

and rapidshare

Some terms associated with pornography, including works like transsexual

Search results are not altered however


Siri

iPhone application that Is an intelligent personal assistant

Is a knowledge finder

Uses human speech You can ask Siri anything…


What Siri Does Not Know

Siri does not know where to find Abortion clinics

Morning-after pill Siri will tell you about

Viagra

Pregnancy Crisis Centers


Why does Siri now know?

Siri mines the web for relevant information to queries Search engines use the same data

Search engines can find local abortion clinics just fine

The null results suggest that the lack of answers is directly programmed into Siri


Question for You

If search results can be manipulated, does that mean our lives and decisions be manipulated as well?


A Brief Word on E-Waste

Disposal of old electronics is a growing problem for our society

Recycling is good but the current industrial practices with it are problematic Third world profiteering

Heavy metal pollution Be aware of the issues and support good

causes/practices when you find them Promote reuse and donations

Question is you need the latest model


Other Aspects of “BAD” IT

Loss of productivity WikiLeaks Anonymous and LulzSec Cyber-bullying Repetitive Stress Injury Guess what this week’s discussion

topics will be?


Summary

IT is not inherently good IT can go bad IT depends on good design, practices,

and policies around its usage


Documents

Fluency with Information Technology INFO100 and CSE100 Katherine Deibel 2012-04-18Katherine Deibel, Fluency in Information Technology1